/*
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* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/sctp.h>
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#include <linux/module.h>
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#include <net/sctp/checksum.h>
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#include <net/netfilter/nf_nat_l4proto.h>
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static u_int16_t nf_sctp_port_rover;
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static void
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sctp_unique_tuple(const struct nf_nat_l3proto *l3proto,
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struct nf_conntrack_tuple *tuple,
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const struct nf_nat_range *range,
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enum nf_nat_manip_type maniptype,
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const struct nf_conn *ct)
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{
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nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
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&nf_sctp_port_rover);
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}
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static bool
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sctp_manip_pkt(struct sk_buff *skb,
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const struct nf_nat_l3proto *l3proto,
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unsigned int iphdroff, unsigned int hdroff,
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const struct nf_conntrack_tuple *tuple,
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enum nf_nat_manip_type maniptype)
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{
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sctp_sctphdr_t *hdr;
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if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
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return false;
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hdr = (struct sctphdr *)(skb->data + hdroff);
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if (maniptype == NF_NAT_MANIP_SRC) {
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/* Get rid of src port */
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hdr->source = tuple->src.u.sctp.port;
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} else {
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/* Get rid of dst port */
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hdr->dest = tuple->dst.u.sctp.port;
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}
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hdr->checksum = sctp_compute_cksum(skb, hdroff);
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return true;
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}
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static const struct nf_nat_l4proto nf_nat_l4proto_sctp = {
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.l4proto = IPPROTO_SCTP,
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.manip_pkt = sctp_manip_pkt,
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.in_range = nf_nat_l4proto_in_range,
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.unique_tuple = sctp_unique_tuple,
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#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
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#endif
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};
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static int __init nf_nat_proto_sctp_init(void)
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{
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int err;
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err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_sctp);
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if (err < 0)
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goto err1;
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err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_sctp);
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if (err < 0)
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goto err2;
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return 0;
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err2:
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nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_sctp);
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err1:
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return err;
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}
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static void __exit nf_nat_proto_sctp_exit(void)
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{
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nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_sctp);
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nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_sctp);
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}
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module_init(nf_nat_proto_sctp_init);
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module_exit(nf_nat_proto_sctp_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("SCTP NAT protocol helper");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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